In many industrial processes a process gas containing pollutants is generated. One such industrial process is the combustion of a fuel, such as coal, oil, peat, waste, etc. In a combustion plant such as a power plant, a hot process gas is generated, often referred to as a flue gas, containing pollutants including acid gases such as sulphur dioxide, SO2. It is necessary to remove as much of the acid gases from the flue gas as possible before releasing the flue gas to the ambient air.
Another example of an industrial process in which a process gas containing pollutants is generated is the electrolytic production of aluminium from alumina. Aluminium may be produced by electrolytic reactions in aluminium production electrolytic cells, sometimes called electrolytic smelting pots, using the Hall-Héroult process. An example of an electrolytic smelting pot is disclosed in US 2009/0159434. The electrolytic reaction occurring in the electrolytic smelting pots produces effluent gas in the form of hot, particle-laden effluent gas, which needs to be cleaned in a gas cleaning unit before being discharged to the atmosphere.
US 2010/0266472 discloses a wet scrubber in which effluent gas enters a wet scrubber housing via an inlet opening arranged in the bottom of the housing. The effluent gas is brought into contact with an absorption liquid inside the wet scrubber housing. The absorption liquid absorbs acid gases, such as sulphur dioxide, from the effluent gas.